Piston for internal combustion motors



Sept. 6, 1938. E. c. LONG 2,129,130

PISTON FOR INTERNAL COMBUSTION MOTORS Original Filed July 30, 1932 V H I /7 1 7 A a p: f ,5 0 2% I d w H 2515 19/ J 3? /2D 44 2e {6 z% 2 w 22 /0 \J 6 z/ /z 7 1 a m 1 5' dim 11 Z'Z- l/zverzfofix EJ77667 djmzrg, Md

' Patented Sept. 6, 1938 UNITED STATES PISTON FOR INTERNAL COMBUSTION MOTORS Elmer 0. Long, Grosse Pointe Park, Mich.

Application July 30, 1932, Serial No. 626,364 Renewed July 6, 1937 11 Claims. (Cl. 309-13) This invention relates to certain imprbvements in a piston for an internal combustion motor and particularly that class of pistons made from an aluminum alloy and is a furthering of the invention disclosed in my U. S. Letters Patent 2,068,341, for Piston, dated January 19, 1987, the

invention of this application having for its primary object to provide the piston with a flexible part in its skirt and with means extending from the opposite side of the piston to the flexiblepart for tending to hold the flexible part from moving too far outwardly as the piston expands under heat.

Another object of the invention is to provide the piston with a flexible skirt portion and with transversely disposed portions below the head which cooperate with the flexible portion of the skirt.

A further object of the invention is to provide the piston with a flexible skirt portion and with transversely disposed portions of material different from the piston which extend from one side of the piston skirt beneath the head to the flexible portion of the skirt.

A still further object of the invention is to provide the piston with a flexible portion on.one side which is providedby slotting the piston and with transversely disposed metallic strips of material different from that of the piston which are molded with the piston and which are disposed above the pin bosses and in cooperable engagement with the flexible portion of the skirt and the opposite side of. the skirt.

Other and further objects will appear in the specification and, be specifically pointed out in the appended claims, reference -being had to the accompanying drawing, exemplifying the invention, and in which: t

Figure 1 is an elevation of this improved piston on the flexible side thereof.

Figure 2 is a transverse vertical section taken approximately on the line IIII of Fig. 1.

Figure 3 is a transverse vertical section taken approximately on the line III-III of Fig. 2.

Figure 4 is an inverted horizontal section taken approximately on the line IV--IVT of Fig. 3.

Referring by numerals to the accompanying drawing, I designates the head of the piston which is cup shaped and having the side wall 2 50 and formed in said side wall are the packing ring grooves 3 and extending from the side wall is a skirt 4.

The pin boss sides 5 of the piston skirt 4 beneath the wall 2 is relieved or cut in as designated at 6 around the pin bosses I, each of which is inwardly extended from respective pin boss sides 5 and formed in each pin boss side above each pin boss is a cored opening 8.

The skirt 4 on one side between the pin boss sides 5 is provided with a tongue shaped portion 9 which is formed by a pair of longitudinal slots I0 which are joined at one end by a transverse slot II, the transverse slot II being formed adjacent the lowermost packing ring recesses 3 and whereas the longitudinal slots I0 extend to a point approximately below the pin bosses 1.

Extending from the open end of the piston and to a distance in the tongue shaped portion 9 is a longitudinally formed slot I 2, said slot at its inner extending end terminating at a distance from the transverse slot II. The forming of the tongue 9 in one side of the piston and the longitudinal slot I2 therein provides a flexible side I3 in the piston skirt 4.

The side of the skirt opposite from the flexible side I3 is the thrust side I4 and embedded in the thrust side I4 of thepiston are the angular formed ends I5 of a pair of transversely disposed members I6, said members having their oppositeangular ends I'l embedded in the tongue portion 9 of the flexible side I3 of the skirt. The pair of members I6 are of a material such as steel, having a much less co-efiicient of expansion than aluminum alloy of which the piston, with the exception of the members I6, is made, and are disposed above the pin bosses and beneath the wall 2 of the head I.

The members I6 are each beveled on their lower edges as designated at IB, said beveled edges being in engagement with respective projections I9, one of which is formed on the top side of each pin boss 1 and in abutment with the top edge of each member I6 is a respective web 20, said webs depending from the head I and extending thereacross. Depending from the head I and disposed between the webs 20 and formed integral therewith is a pair of webs 2| and in sidewise connection with each of the webs 20 and depending from the head I is a pair of legs 22., each pair of legs at their lower ends being formed integral with respective pin bosses 'I In the manufacture of a piston of this improved character which is preferably die cast, a pair of oppositely sidewise disposed metallic cores are inserted in the mold, said cores engaging at their ends in the aperture 23 of respective members I6 for holding the members in-place. Another core or cores is then inserted longitu-' dinally through the lower end of the mold and the mold is then ready for the pouring operation.

the appended claims.

After the piston has been cast, the transverse slot I I is formed by saw cutting and the cut in addition to passing through the wall of the pis-' ton skirt will also cut through the lower portions of the webs 29 at one end as shown in Fig. 2, and longitudinal saw cuts provide the slots I 0. Before cutting the slot I2, an aperture 24 is drilled in the side I3 of the piston and the slot I 2 is then formed so as to terminate in the aperture 24. This aperture is for the purpose of forming a terminus for the slot I2, so that the slot will not tend to extend further by splitting which might be brought on in the operation of the piston by flexing of the side I3 of the skirt.

In the operation of a piston of this improved character in a cylinder of an internal combustion motor, the head I obviously will receive more heat than the remaining part of the piston, and

as the head expands diametrically across the pin boss axis, the pin bosses will tend to be carried outward by the pairs of legs 22 depending from the head and the central portion of each of the members I6 will tend to be moved outwardly from one another thereby tending to shorten the length of said members and as the members I6 are connected at I! to the tongue portion 9 on the flexible side I3 of the piston, said members will tend to draw or hold the tongue portion 9 inward. As the piston head, I is smaller in-diam- .eter than the skirt 4 and the pin boss sides 5 are relieved as designated at 6, the longitudinal slot I2 will provide means for relieving excess expansion of the lower part of theskirt 4 across the pin boss sides and the pulling in tendency of the members I6 on the tongue portion 9 will tend to constrain the thrust sides of the piston and particularly the flexible side l3 from excess expansion.

The engagement of the webs 20 with the upper edges of the members I6, and the engagement of the lower edges of the webs with the top sides of the pin bosses I will prevent distortion of the members I6, and the projections I9 will tend to pull the intermediate portions of the members outwardly from each other as the pin bosses are moved outward by expansion of the head.

On account of the manner in which the members l6 engage the webs 20 and 2| and the-pin bosses I, said members I6 are free to slide with respect to said webs and the pin bosses. .This slidable relationof the members I6 will permit them to exert a pulling tendency on the tongue shaped portion 9 as said members are pulled by the action of the normal expansion of the thrust side I4 of the piston. As the tongue shaped portion 8 is flexibly connected to'the skirt 4, the tongue shaped portion 9 will therefore always follow the bearing side I4 and consequently the diameter of the skirt will remain approximately the same during thermal conditions of the piston.

While but one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that particular embodiment or otherwise than by the terms of What I claim is:

1. A piston comprising a head and a skirt having opposing thrust sides, said skirt being slotted on; one of its thrust sides for providing a flexible portion therein, a pair of transverse members of a material having a'low coefiicient of expansion connecting said flexible portion to the opposite side of the skirt, and a pair of webs depending from the head and having their lower ends in abutment with the top of respective members.

2. A piston comprising a head having a side wall and a skirt having opposing thrust sides, one of the thrust sides being flexibly formed and separated irom the side wall of the head and the other thrust side being continuous with the side wall of the head, a pair of transverse members of a material having a low coeilicient of expansion connecting said flexible thrust side to the opposite thrust sideof the skirt, and a pair of webs depending from the head having their lower ends in abutment with the top of respective members.

3. A piston comprising a head having a side wall and a skirt having opposing thrust sides, opposing pin boss sides in the skirt and a pin boss extending from each pin boss side, one of the thrust sides being flexibly formed and separated from the side wall of the head and the other thrust side being continuous with the side wall of the head, a pair of transverse members of a material having a low coefllcient of expansion connecting said flexible thrust side to the opposite thrust side of the skirt, each member having bearing association with a respective pin boss, and a pair of webs depending from the head having their lower ends in abutment with the top of respective members.

4. A piston comprising a head and a skirt having opposing thrust sides, said skirt being slotted on one of its thrust sides for providing a flexible portion therein, a transverse member of a material having a low co-eflicient of expansion connectingsaid flexible portion to the opposite side of'the skirt, and a web depending from and extending across the head and having its lower end in abutment with the top of said member.

5. A piston comprising a head having a side wall and a skirt having opposing thrust sides, one of the thrust sides being flexibly formed and separated from the side wall of the head and the other thrust side being continuous with the side wall of the head, a transverse member of a material having a low coefllcient of expansion connecting said flexible thrust side to the opposite thrust side of the skirt,and a web depending from the head and having its lower end in abutment with the top of said member.

6. A piston comprising a. head, a skirt having opposing thrust sides, and strut means of mate- .rial difl'erent from the skirt connected to said thrust sides and substantially abutting a part extending across the piston head and being capable of independent longitudinal movement relative to said part.

'7. A piston comprising a head, a skirt having opposing thrust sides, web means depending from the head, and strut means having a low coeiflcient of expansion joining said thrust sides and disposed in substantial paralleling abutment with said web means and being free of interlocking engagement with said web means.

8. A piston comprising a head having a ringland, a skirt having opposing thrust sides, web means depending from and extending across the head and joining the ringland, and strut means having a low co-eflicient of expansion joining said thrust sides .;and disposed in substantial paralleling abutment with said web means and said strut means being free to slide relative to said web means,

9. A piston comprising a head, a skirt having opposing thrust sides, and strut means connected to said thrust sides and extending across the head, said strut means being free of interlocking engagement with said head.

10. A piston comprising a head, a skirt having opposing thrust sides, and strut means of material difierent from the skirt connected tosaid thrust sides and substantially abutting a part across the piston head, said strut means and said part with which it substantially abuts, being capable of free movement relative to one another.

11. A piston comprising a head having a side wall, a web integral with said head and its side wall, a skirt having a pair of thrust sides, one of said thrust sides depending from the side wall 

